LTE-A系统中基于小区参考信号的信道估计算法  

Channel estimation algorithm based on cell reference signal in LTE-A system

作　　者：李慧敏 张治中[1,2] 李琳潇 LI Huimin;ZHANG Zhizhong;LI Linxiao(Test Engineering Research Center of Communication Networks,Chongqing University of Posts and Telecommunications,Chongqing 400065,China;Chongyou Huice Communications Technology Company Limited,Chongqing 401121,China)

机构地区：[1]重庆邮电大学通信网与测试技术重点实验室,重庆400065 [2]重庆重邮汇测通信技术有限公司,重庆401121

出　　处：《计算机应用》2018年第7期2009-2014,共6页journal of Computer Applications

基　　金：国家科技重大专项(2015ZX03001013);重庆市重点产业共性关键技术创新专项(cstc2017zdcy-zdzx0030)~~

摘　　要：增强型长期演进(LTE-A)系统中,通常利用插值算法估计出所有数据位置的信道频率响应值。针对传统的线性最小均方误差(LMMSE)算法需要预先获取信道统计特性,矩阵实时求逆运算量大的问题,提出了一种改进的频域LMMSE信道估计插值算法。首先通过导频插值来增加虚拟导频,以此提升算法性能;然后借助时域内的信道能量比较集中的优势,给出了自相关矩阵和信噪比的近似估计方法;最后采用滑动窗方法进一步简化算法复杂度,从而完成频域LMMSE插值。仿真结果表明,所提算法总体性能优于线性插值以及基于离散傅里叶变换(DFT)的插值方法,且与传统LMMSE插值算法具有相近的误码率(BER)和均方误差(MSE);但与传统算法相比,运算次数降低了98.67%,实现了算法性能与复杂度的较好折中,适用于实际的工程应用。Interpolation algorithms are usually used to estimate the channel frequency response value at the data location in Long Term Evolution-Advanced （LTE-A） system. Concerning the problem that traditional Linear Minimum Mean Square Error （LMMSE） algorithm needs to obtain channel statistical properties in advance and it suffers from a high computational complexity due to an inversion matrix operation, an improved LMMSE channel estimation interpolation algorithm was proposed. Firstly, the pilots were interpolated to add virtual pilots, which improved the performance of the algorithm. Secondly, an approximate estimation method of autocorrelation matrix and Signal-to-Noise Ratio （SNR） was given by using the fact that channel energy in the time domain is more concentrated. Finally, a sliding window method was adopted to further simplify the algorithm complexity to complete the LMMSE interpolation in frequency domain. The simulation results show that the overall performance of the proposed algorithm is better than that of linear interpolation method and Discrete Fourier Transform （DFT） interpolation method, and it has similar Bit Error Rate （BER） and Mean Squared Error （MSE） performance with the traditional LMMSE interpolation algorithm. Furthermore, it reduces the complexity by 98.67% compared with traditional LMMSE estimator without degrading the overall BER and MSE performance, so it is suitable for practical engineering applications.

关 键 词：增强型长期演进 信道估计 线性最小均方误差 插值算法 时延 

分 类 号：TN929.5[电子电信—通信与信息系统] TP393[电子电信—信息与通信工程]